Grossbritannien und Irland: Funkstellen [Great Britain: Radio Transmitters/Stations]; Grossbritannien und Irland: Fernsprech und Telegraphennetz [Great Britain: Telephone and Telegraph Network]
Generalstab des Heeres [German General Staff] :: Berlin: [Department for War Maps and Surveying], 1941.
This scarce and very large (47 inches x 35 inches, 120 cms x 89 cms) German double-sided military intelligence map, 1.IX.1940 Nach den bisher vorliegenden Unterlagen, bearbeitet ... (1st September 1940, Taken from available documents ...) shows the locations of Britain's wartime radio stations including ...
Funkstelle der kriegsmarine (Navy radio transmitter)
Funkstelle der Luftwaffe mit Peilsender (Air Force transmitter with direction-finding),
Funkstelle der Luftwaffe mit Sprechfunk (Air Force transmitter with voice transmission)
One side of the map shows Britain's radio transmitters, the other side Britain's telephone and telegraph network. This information - particularly the Air Force direction-finding transmitter locations - was of clear strategic importance in planning offensive action against Britain whether a land invasion or bombing raids.
However, although the Germans had mapped this network of radio-transmitting stations, they failed to appreciate its significance as being vital to Britains radar defences in making up the linked 'Chain Home' system. This oversight, inter-alia, was a major contributory factor to the Luftwaffe's defeat by the radar-assisted RAF in the Battle of Britain.
Following the Battle of Britain in 1940, the Germans postponed their plans for Unternehmen Seelöwe (Operation Sealion), the invasion of Britain by large-scale troop landings along the South Coast. However, whilst abandoning their immediate plans to invade, the German High Command continued to gather together detailed information to prepare the ground for any future invasion or occupation of Britain.
This double-sided map was issued in Berlin in 1941 as part of Militärgeographische Angaben uber England (effectively translating as Military/geographical Report on England) by Abteilung fur Kriegskarten und Vermessungswesen (Department for War Maps and Surveying), and was intended Nur fur den Dienstgebrauch (For official use only) by the Generalstab des Heeres (German General Staff).